For the improvement of the stability of vulcanized rubber articles as for example tires, conveyor belts, V-belts, hoses and the like against mechanical deformation as is known these are reinforced with plies. Such composite articles have plies or inner or outer layers of textile fibers or textile fiber structures such as fabrics and fleeces, or metal wires or metal wire structures such as, e.g. steel cord, which also can have a coating such as e.g. of brass, zinc or the like. Glass fibers or glass fiber structures also have been used already as ply materials.
The firm anchoring or adhesion of the ply materials with the rubber vulcanizate is important in order that there be attained a good service life of the dynamically required molded articles. Thus it is known to partially replace the carbon black filler in the rubber mixture by silica filler in order to produce a high adhesion (German Pat. No. 1620786 and related Klotzer U.S. Pat. No. 3,687,719). Further substantial improvement in adhesion is produced as is known by adding to the known rubber mixtures components capable of forming synthetic resins such as phenol and/or amine and aldehyde or aldehyde splitting off compounds. Resorcinol and hexamethyleneteteramine find a wide use as resin forming components in rubber adhesive mixtures (British Pat. No. 801,928, French Pat. No. 1021959) in a given case in combination with silica filler (German AS No. 1078320).
Because of its poor dispersibility resorcinol is difficult to work into rubber adhesion mixtures. Therefore there are mostly used more easily dispersible mixtures of resorcinol with a silica filler (German Pat. No. 1301478 and related Klotzer U.S. Pat. No. 3,778,406) as, e.g. the commercial product Cofill.RTM.11 of Degussa, which is a 1:1 mixture of resorcinol and a specific silica filler. To be sure in this product the customery clumpy or scaly resorcinol is present in homogenously distributed form, but the product also shows disadvantages. Thus there can occur undesired dust development in processing.
Also the mixture reduces only slightly or not at all the tendency of resorcinol to sublimation from the rubber mixture at the customary processing temperatures as a result of which exhaustors are required for the purification of the work air. Also something is left to be desired in regard to easy dosability and flowability of the powdery product.
Therefore it was the problem of the present invention to discover a resorcinol containing preparation which is present in homogeneous distribution, has good flowability and dosability, preferably does not dust in the weighing and mixing procedure, has good dispersability in rubber mixtures and whose resorcinol portion shows a reduced sublimation, without the quality of the rubber molded article produced there-with being impaired, thus especially neither reducing the physical rubber properties, nor especially its good adhesion properties between plies and rubber.